An Adventure in Childhood
by Swiftwidget
Summary: Toshinori and Izuku are ambushed by a villainess with a Regression Quirk. Izuku gets to meet his childhood hero for the first time again. Toshinori takes a speed course in fatherhood. Class 1A thinks Mini Izuku is adorable. Shenanigans follow. Purely fluff and silliness. Very fun to write.


I do not own BNHA or its characters.

I have no self control and I apparently can't stick to just writing two fics at a time...

* * *

 **An Adventure in Childhood - Part 1**

 **Oh Boy…**

How could a simple grocery run for the dorm turn into such a disaster?

Izuku Midoriya and Toshinori Yagi were surrounded, their backs to the building behind them and nowhere to run. Izuku stood his ground in front of the slight form of All Might, glaring determinedly at the three villains that had ambushed them on the busy city street.

Izuku's mind raced as he examined each villain. Two men at his one and two o'clock and a woman at his ten. The first man was a young and scrawny mutant-form. What he lacked in muscle he made up for with hard-looking skin and bony spikes erupting from his arms, shoulders, and back. Likely a close range fighter and more defensive and panicky by the way he hung back, eyes darting between his comrades. The second man was slightly older, perhaps early thirties, and surrounded by floating stones that orbited him slowly. Some kind of telekinetic quirk or perhaps a gravity quirk? Either way, the villain was already down a projectile. A swift Shoot Style kick sent the stone he'd flung apparently out of the man's range of control. The woman was a mystery. She guarded the left side alone, so Izuku assumed she had a long range or fast quirk. Her hair appeared to be made of some kind of silvery liquid that draped over her shoulders and wrapped around her arms. Her hands were each completely engulfed in an orb of the substance. She hung back a ways, her eyes never leaving Toshinori.

Apprehension flared in Izuku's gut. The way the woman looked at Toshinori… He was her target. The two men were likely a distraction that would allow her to act.

Izuku glanced back at All Might. He must have already figured the woman out. He had moved to Izuku's right side, frowning in irritation at the villainess.

Worried and angry shouts and panicked phone calls to police came from across the street where a crowd of bystanders had gathered. Suddenly, someone at the edge of the crowd pointed up and yelled "Kamui Woods! Backdraft!"

The Pro Heroes entered the scene, dropping down from the roof above and landing in front of Izuku and All Might. They quickly moved to action. Kamui jumped at the telekinetic man, his arm splitting and branching as he knocked the flung projectiles away. Backdraft turned from the villains to Izuku and All Might.

"Are you two alright?" the hydrokinetic hero asked.

All Might threw up a thumbs up in reply.

"Shit!" The spiked villain suddenly exclaimed. Panic seized him and he bolted.

"No you don't!" Backdraft rushed forward and shot a powerful stream of water, knocking the younger villain over.

Whatever happened next, Izuku missed. The female villain rushed toward All Might, a snarl on her face.

Izuku tensed and activated One for All. With a grunt, he tossed his bag of canned goods at the woman. She ducked away and cursed when the heavy bag clipped her shoulder as it shot past.

"Fuck this!" she spat.

The woman lunged, but not for All Might. Izuku jumped back with a yelp but too late. Her arm shot out, her hand clasping over Izuku's mouth, freezing metallic liquid smacking him in the face and blinding him. His surprised shout left him vulnerable and the viscous liquid rushed into his mouth and nose. Then a hard strike to his gut made him gasp and choke, the heavy liquid filling his lungs and stomach and sending a numbing sensation through his limbs. Then the blinding liquid was gone and Izuku could see again. The woman growled and cursed as she was dragged away and forced to the ground by the binding hold of Kamui Woods.

Izuku dropped to his hands and knees, coughing and retching between broken gasps for air, growing panicked as his lungs burned and none of the liquid left him. A firm hand squeezed his shoulder and another thumped the boy's back roughly until Izuku could breath again.

"Are you alright, my boy?" All Might asked, squeezing Izuku's shoulder urgently, "Midoriya?"

Izuku shook his head and covered his mouth with a hand. He felt feverish and cold; the feeling of that freezing slime still sat heavily in his chest and abdomen. Nausea flared in his gut and his whole body ached. He grit his teeth against a foreign pain in his chest that spread outward until his whole body felt pressed in a vice.

"Hurts," Izuku ground out, his voice higher and strained. The world tilted. Firm hands caught him and held him steady.

"Midoriya!"

Somewhere off to the side the villainess laughed as Kamui woods hauled her to her feet. "Have fun babysitting the brat!"

"All Mi- hrk!" Izuku doubled over as his vision swam and the pain intensified in his bones. He felt like he was being crushed from all sides.

The grip on his shoulders tightened and shifted.

A moment longer and Izuku thought he'd pass out, then the pain abruptly receded. He sat curled in on himself with eyes shut tight, breathing raggedly and trembling. He felt so small and weak, like he'd only just broken a terrible fever.

"Midoriya, my boy? You're-"

Izuku groaned and slowly opened his eyes, sitting up and cringing at the bright sunlight, and looked down.

What?

Izuku's clothes hung off his body loosely, pooling on the sidewalk that looked much closer than it had moments before. He furrowed his brow and lifted his hands. They barely reached the elbow of his sleeves.

"What?" Izuku clapped his hands over his mouth. That did not sound like his voice!

A massive hand covered his shoulder and Izuku flinched away with a high pitched yelp, nearly tumbling over the tangle of oversized clothes before the hand darted forward to support his back.

"Midoriya, it's me. Calm down," Toshinori said gently, brows raised in concern and rubbing circles on the boy's back.

Izuku's eyes widened and he stared. Toshinori was huge … or maybe? A thought dawned on Izuku and he looked down at his own arms covered in too big sleeves. Slowly he bunched up the sleeves until he'd freed his hands. They were so small … like a child's.

"… All Might?" Izuku's too young voice shook. "What happened to me?"

"Ah, well," Toshinori took out his phone, tapping the screen, "It seems she had an age manipulation quirk of some kind-"

"A-age?!" Izuku exclaimed, or at least that had been his intent. It came out more like a squeak.

"Here," Toshinori held out his phone.

Izuku took the cellphone, fumbling with the weight a little. His hands looked so small curled around the edges of it he almost forgot to look at the screen. Then he did.

"W-w-w-what?!" Izuku held the phone out at arm's length, which wasn't very far, and gaped at the image on the screen. He looked like he did in his mom's old photographs, small and round-faced. His school shirt slipped off one of his small shoulders. "No way… I look like a kid…"

Toshinori nodded and took back the cellphone. He shot the boy a teasing smile, "You sound like one too."

"All Might!" Izuku squeaked, blushing furiously and covering his mouth. He groaned in embarrassment, holding his head in his arms.

Toshinori chuckled and ruffled the boy's hair, more unruly than ever. He glanced up when the hero Backdraft jogged up to them.

"All Might! Are you and your student okay?" the hydrokinetic hero asked, then looked down at Izuku, "O-oh…"

"Hi." Izuku waved awkwardly, the sleeve of his school shirt slipping back over his hand.

"You okay, kid?" Backdraft asked. "Besides the obvious, I mean. Any bumps or bruises?"

"Um, I think I'm alright?" Izuku said, patting himself down. Nothing hurt anymore. There was just a small fuzzy sensation behind his eyes and the odd feeling that he was forgetting something. But that wasn't anything to worry about… probably?

"I'm sorry," the firefighter hero said, kneeling down to Izuku's eye level, "I didn't protect you from that villainess. She's been causing some trouble for a while with that regression quirk of hers. We should have caught her sooner."

Izuku jolted, waving his hands frantically, "N-no! It's okay! I want to be a hero anyway and this is a part of the job right? It's bound to wear off soon anyway. Physical manipulation quirks have a time limit if they aren't reversed by the user."

"That's true! You're sharp! As expected of a U.A. student," Backdraft said, a smile in his voice though the mask hid his face. He gave the boy a pat on the shoulder with a water-made hand before standing, "Well, time to clean up the scene. Need any help getting back to the school?"

Toshinori shook his head, "We should be able to get back to U.A. alright. I'll call for someone to pick us up."

Backdraft nodded and waved farewell before rejoining Kamui Woods on the other side of the street.

"Back to U.A.? Why … Why would we go there now?"

Toshinori looked down at Izuku, tensing warily at his odd tone. The boy's expression was pinched in confusion and he put a hand to his forehead. Confusion turned quickly to growing unease.

"All Might… I don't - Something's wrong," he gripped a portion of his curly hair, "No, I live there, right? The dorms? Or… I feel a little dizzy."

Toshinori's brows rose in alarm and he gently turned Izuku's shoulders so he was facing him. Just as gently, he ran a hand over the boy's head, feeling for any bumps, "Did you hit your head? Does it hurt?"

"N-no? Just … I don't feel right. I can't -" Izuku bit his lip, a small panicked light shining in his eyes. "Where…? Why are we in town?" The boy wrapped his small arms around himself and glanced around, a small tremble running down his thin frame.

"Midoriya, look at me," Toshinori gently turned the boy to look at him again, "Do you remember what we were doing today, my boy? Izuku?"

"I, um… I can't remember," Izuku furrowed his brows and shook his head, curling into himself more. He met Toshinori's gaze and uncertainty shifted to fear, "Who are you? How do you know my name? W-where's my mom?"


End file.
